Drill steel rotation mechanism



Search Hoor @WAN Patented June 1, 1937 UNITED STATES Search nom PATENT OFFICE DRILL STEEL ROTATION MECHANISM Elmer G. Gartn, Claremont, N. H., assigner to Sullivan Machinery Company, a corporation of Massachusetts Application July 13, 1936, Serial No. 90,307

9 Claims.

This invention relates to rock drills, and more particularly to improvements in the drill steel rotation mechanism of rock drills of the pressure uid actuated, hammer type.

An object of this invention is to provide an improved rock drill rotation mechanism. Another object is to provide an improved rotation mechanism for the drill steel of a rock drill of the pressure uid actuated, hammer type. A further object is to provide an improved drill steel rotation mechanism controlled by the valve mechanism of the fluid distribution means of the rock drill hammer motor, whereby, when the return movement of the hammer piston is effected, a rotative movement is transmitted to the drill steel. Still another object is to provide an improved drill steel rotation mechanism of the type wherein a rifle bar is slidingly interlocked with the hammer piston, and embodying improved means for intermittently holding the rifle bar stationary to effect rotation of the drill steel. These and other objects of the invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown 25 for purposes of illustration one form which the invention may assume in practice.

In this drawing:-

Fig. 1 is a view in longitudinal section of a hammer rock drill having embodied therein the 30 illustrative form of the improved drill steel rotation mechanism.

Fig. 2 is a fragmentary sectional View taken in the plane of Fig. 1, showing parts in a diiferent position.

Fig. 3 is a view similar to Fig. 2, showing parts in still another position.

Fig. 4 is a cross sectional view taken substantially on line 4-4 of Fig. 2.

In this illustrative embodiment of the inven- 40 tion, there is shown a rock drill, herein of the pressure fluid actuated hammer type, comprising a motor cylinder I having a bore 2 containing a reciprocatory. hammer piston 3. The hammer piston has a forwardly projecting striking bar 4 45 guided in a bore 5 in the forward cylinder head 6,

and this striking bar is adapted to transmit the impact blows of the hammer piston to the shank l of a usual rock drill steel 8. The drill steel shank is supported within a chuck bushing 50 9 mounted in a chuck sleeve Ill, in turn rotatably mounted in a front chuck housing II secured to the cylinder. Arranged in a bore I2 alined with the cylinder bore at the rear end of the latter is a combined rear head block and valve box I3,

55 while arranged centrally therein is a valve guide member I4 formed integral within a circular plate I5 abutting the rear face of the valve box. Guided on the member I4 and reciprocably mounted in a valve chamber I6 formed in the valve box is an automatic fluid-actuated, fluid distributing valve I'I for controlling the supply of pressure fluid to and the exhaust of fluid from the motor cylinder in a well known manner. Mounted in a rear head block I8 secured to the cylinder is a throttle valve I9 for controlling the supply of pressure fluid through passage 20 to a pressure'chamber 2I; and a longitudinal fluid conducting passage 22 connects the chamber 2| with an annular recess 23 formed in the walls of the valve chamber. A large axial passage 24 connects the forward end of the Valve chamber directly with the rear end of the cylinder bore, while an annular groove 25 formed in the exterior periphery of the valve connects, when the valve is in its forward position, the recess 23 with an annular groove 26, in turn connected through a passage 2l with the forward end of the cylinder bore. VAlso formed in the wall of the valve chamber is an annular groove 28 connected by an exhaust passage 29 directly to atmosphere. When the distributing valve I'I is in the position shown in Fig. 1, pressure fluid may flow from the throttle valve I9 through passage 20, chamber 2I, passage 22, recess 23, through the valve chamber past the forward end of the valve and through the axial passage 24 to the rear end of the cylinder bore,.the pressure fluid acting on the rear pressure area of the hammer piston to drive the latter forwardly to strike its blow on the drill steel shank. When the rear edge of the hammer piston overruns a throwing passage 30, pressure fluid is conducted from the rear end of the cylinder bore through the throwing passage to the rear end of the valve chamber, the pressure fluid acting on the rear pressure area of the valve to throw the latter forwardly from the position shown in Fig. 1 to the position shown in Fig. 3. When the valve is in the position shown in Fig. 3, pressure Huid may flow from the throttle valve I9 through the passage 20, chamber 2|, passage 22, recess 23, through the annular groove 25 on the valve periphery and through groove 26 and passage 21 to the forward end of the cylinder bore; the pressure fluid acting on the forward pressure area of the hammer piston to move the latter rearwardly to effect its retractive stroke. As the hammer piston moves toward the end of itsy rearward stroke, a relatively high compression pressure is built up within the cylinder bore, and this compression pressurel acts on the forward pressure area of the valve to throw the latter rearwardly from the position shown in Fig. 3 to its initial position shown in Fig. 1. The operations above described are repeated in rapid sequence during operation of the hammer motor.

Now referring to the improved rotation mechanism for the drill steel, it will be noted that the piston striking bar 4 has formed on the exterior surface thereof longitudinal straight grooves 3I slidingly interlocked with straight keys 32 formed on a chuck bushing 33 threadedly fixed within the chuck sleeve I0. Rotatably mounted Within an axial bore 34 in the valve guide member I4 and extending centrally through the valve I1 and the valve box is a rotation bar 35 having spiral grooves 36 slidingly interlocked with spiral keys formed on a rifle nut 31 secured within the hammer piston. The rearward portion of the rotation bar is formed with a cylindrical enlargement 38 projecting within a central b ore 39 formed in a stationary plate 40 interposed between the plate I and an annular block 4I, the latter having a central bore 42 in which is reciprocably mounted the annular liange 43 of a clutch sleeve 44 surrounding and reciprocably guided on the rotation bar enlargement 38. The clutch sleeve 44 is splined at 45 to the rotation bar enlargement so that it rotates with the rotation bar, but is axially reciprocable with respect to the rotation bar. The body of the sleeve is guided in a bore 46 formed in a rear end plate 41 interposed between the block 4I and the rear head block I8. The rear face of the rear plate 40 is formed with projecting clutch teeth 48, while the forward face of the sleeve flange 43 is formed with projecting teeth 49. A passage 50 connects the supply passage 21 with the bore 42 at the rear side of the sleeve flange 43 and the rear face of the sleeve flange forms a rear pressure area on which pressure uid is adapted to act to move the sleeve forwardly axially in its bore with respect to the rotation bar to bring the projecting clutch teeth 49 on the sleeve flange into interlocking engagement with the projecting clutch teeth 48 on the stationary plate 40. The bore 46 at the rear side of the sleeve body is vented to atmosphere through a small passage 5I. Mounted in a bore 52 formed in the cylinder is a manually controllable rotary valve 53 having a passage 54 extending therethrough, and a right-angle passage 55, and this valve, when rotated counter-clockwise through 90, cuts off communication of the passage 5Ilswith the groove 26 of the fluid distribution means so that no pressure fluid will be able to flow from the groove 26 through passage 50 to the bore 42 at the rear side of the clutch sleeve flange 43, and connects the rear end of the bore 42 to atmosphere through a small vent passage 56.

The operation of this improved drill steel rotation mechanism Will be clearly apparent from the description given. When the parts are in the position shown in Fig. 3, pressure fluid may flow from the throttle valve I9 through passage 20, chamber 2|, passage 22, recess 23, through the annular groove on the valve periphery, and through recess 26, Ypassage 21 and passage 50 to' the bore 42 at the rear side of the clutch sleeve flange 43, the pressure acting on the rear pressure area of the clutch sleeve flange to move the clutch sleeve forwardly to lock the rotation bar 35 against rotation. As the hammer piston moves rearwardly, the spiral grooves 36 of the then stationary rotation bar engaging the spiral keys of the rie nut cause the hammer piston to have a rotative movement, and this rotative movement of the hammer piston is transmitted through the straight grooves on the piston striking bar 4, the straight keys 32 on the chuck nut 33, the rotatable chuck sleeve I0 and chuck bush- 5 ing 9 to the drill steel. When the distribution valve I1 is thrown from the position shown in Fig. 3 to the position shownin Fig. 1, the pressure area on the rear side of clutch sleeve flange 43 is connected to atmosphere through passage 10 50, recess 26, the annular groove 25 on the valve periphery and the groove 28 communicating with the exhaust passage 29, so that, when the hammer piston starts its forward working stroke, the clutch teeth 49 on the clutch sleeve 44 are l5 kicked out of engagement with the clutch teeth 48 on the stationary plate 4D, the clutch sleeve moving rearwardly from the position shown in Fig. 1 into the position shown in Fig. 2 at that time. The rotation bar 35 is thus free for rotary 20 movement so that the hammer piston, as it moves forwardly to effect its working stroke, has no rotary motion, the rotation bar rotating freely within the bore 34 in the guide member I4. When the valve is again thrown to the position shown 25 in Fig. 3, the clutch sleeve 44 is moved forwardly by the action of pressure fluid thereon into its clutched relation with the stationary plate 40, so that the rotation bar 35 is again held against rotary motion and a rotary motion is again imparted to the hammer piston, these operations being repeated rapidly during operation of the motor. When the valve 53 is rotated counterclockwise 90, the supply of pressure fluid t0 the i bore 42 at the rear side of the clutch sleeve flange 30 43 is cut off, and the space to the rear side of the clutch sleeve flange is vented as above described by passages 50, 55, 54, 56, so that the I rotation bar is at all times free to rotate, and no rotative movement is, at that time, impartedggll) to the drill steel.

It will be evident that, if desired, pressure fluid could be supplied constantly to the bore 46 at the rear side of the sleeve body so that the clutch sleeve 44 is constantly urged toward its clutched 45 position, and it will also be evident that the pressure area at the rear side of the sleeve flange 43 may be so proportioned that, when the rotation mechanism for any reason becomes overloaded. the sleeve will move automatically against the opposing pressure into its released position, by the action of the pressure fluid thereon to interrupt the drill steel rotation until the overload on the rotation mechanism is removed. It will also be noted that, if desired, the stationary clutch 55 teeth may be formed on'the forward face of the plate 41 and the clutch teeth 49 formed on the rear face of the sleeve flange 43 and the passage 50 arranged so that it communicates with the bore 42 at the forward side of the sleeve flange, 60 thereby to move the clutch sleeve rearwardly into its position to lock positively the rotation bar to the stationary plate.

,As a result of 'this invention, it will be noted that an improved drill steel rotationrmechanism is provided whereby control of the rotation bar is effected in a comparatively simple and efficient manner. It will further be noted that, by connecting the controlling passage 50 for the clutch member to a fluid supp-ly passage'of the motor, 70 the rotation mechanism is controlled automatically by the fluid distributing valve of the fluid distribution means of the drill hammer motor. It will further be evident thatby splining the reciprocable clutch member directly to the rotation CII bar, bodily movement of the rotation bar is obviated, so that control of the rotation bar is effected by a part comparatively light in weight. Other uses and advantages of the improved drill steel rotation mechanism Will be clearly apparent to those skilled in the art.

While I have in this application specically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration, and that the invention may be further modified and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. A drill steel rotation mechanism comprising a rotation bar, a reciprocable member arranged coaxially with and splined to said rotation bar, a stationary member, clutch teeth on the reciprocable and stationary members adapted to engage each other to lock positively the rotation bar against rotation, said reciprocable member having a pressure area, and means for intermittently supplying pressure uid to act on said pressure area to move said reciprocable member intermittently into clutched relation with said stationary member. l

2. A drill steel rotation mechanism comprising a rotatable rotation bar, a reciprocable clutch member arranged coaxially with and connected to said rotation bar for rotation therewith, said clutch member connected to said rotation bar for reciprocatory movement with respect thereto, a stationary member, clutch teeth formed on said reciprocable and stationary members adapted to engage each other to lock positivelysaid rotation bar against rotation, said reciprocable member having a pressure area, and means for intermittently supplying pressure uid to act on said pressure area to move said reciprocable member intermittently into clutching relation with said stationary member.

3. In a rock drill, the combination with a hammer motor having a reciprocating hammer piston for imparting a. blow to the shank of a drill steel, of a rifle bar slidingly interlocked with said piston, means for intermittently holding said rifle bar against rotation to cause a rotary motion to be imparted to the hammer piston during one stroke of the latter, and connections between said hammer piston and the drill steel for transmitting the rotary mo-tion of said piston to the drill steel, sai'd means for intermittently holding said rie bar against rotation comprising a reciprocable member coaxial with and splined to said rifle bar, a coaxial stationary member, clutch teeth on said reciprocable and stationary members adapted to engage each other to lock positively the rie bar tosaid stationary member, said reciprocable member having a pressure area, and means for subjecting said pressure area intermittently to the action of pressure uid.

4. In a rock drill, the combination with a hammer motor having a reciprocating hammer piston for imparting a blow to the shank of a drill steel,

oi a riile bar slidably interlocked with said piston, means for intermittently holding said rifle bar against rotation to cause a rotary motion to be imparted to the hammer piston during one stroke oi the latter, and connections between said hammer piston and the drill steel for transmitting the rotary motion of said piston to the drill steel, said means for intermittently holding said rifle bar against rotation comprising a reciprocable Search Roon member coaxial with and splined to said rie bar, a coaxial stationary member, clutch teeth on said reciprocable and stationary members adapted to engage each other to lock positively the rifle bar to said stationary member, said reciprocable member having a pressure area, and means for subjecting said pressure area intermittently to the action of pressure fluid, said rifle bar holding means also including means for connecting said pressure area to exhaust during the intervals when said area is not subjected to pressure uid.

5. In a rock drill, the combination with a hammer motor having a cylinder containing a reciprocating hammer piston, and fluid distribution means including a uid actuated iluid distributing valve for controlling the supply of pressure fluid to said cylinder to effect reciprocation of said hammer piston, of drill steel rotation means comprising a rotation bar slidingly interlocked with said hammer piston, means for intermittently holding said rotation bar against rotation to cause the same to impart a rotary motion to the hammer piston during one stroke of the latter, and means connected to the hammer piston for transmitting the rotary motion of the latter to the drill steel, said means for intermittently holding said rotation bar against rotation comprising a reciprocable member coaxial with and connected to said rie bar, a stationary member, clutch teeth on said stationary and reciprocablevmembers adapted to engage each other to lock positively said rifle bar to said stationary member, said reciprocable member having a pressure area adapted to be intermittently subjected to the action of pressure uid, and means controlled by said iluid distributing valve for intermittently subjecting said pressure area to the action of pressure fluid.

6. In a rock drill, the combination with a hammer motor having a cylinder containing a reciprocating hammer piston, and uid distribution means including a fluid actuated uid distributing valve for controlling the supply of pressure fluid to said cylinder to eiect reciprocation of said hammer piston, of drill steel rotation means comprising a rotation bar slidably interlocked with said hammer piston, means for intermittently holding said rotation bar against rotation to cause the same to impart a rotary motion to the hammer piston during one stroke of the latter, and means connected to the hammer piston for transmitting vthe rotary motion of the latter to the drill steel, said means for intermittently holding said rotation bar against rotation comprising a reciprocable member coaxial with and connected to said rifle bar, a stationary member, clutch teeth on said stationary and reciprocable members adapted to engage each other to lock positively said rifle bar to said stationary member, said reciprocable member having a pressure area adapted to be intermittently subjected to the action of pressure fluid, and means controlled by said iluid distributing valve for intermittently subjecting said pressure area to the action of pressure fluid and for intermittently connecting said pressure area intermittently supplying pressure uid to act on said pressure area to move said reciprocable member` intermittently into clutched relation With said stationary member having a controlling valve operable at will for interrupting the flow of uid to said pressure area.

8. In a rock drill, the combination with a hammer motor having a reciprocating hammer piston for imparting a blow to the shank of a drill steel, of a rifle bar slidingly interlocked with said piston, means for intermittently holding said rifle bar against rotation to cause a rotary motion to be imparted to the hammer piston during one stroke of the latter, and connections between said hammer piston and the drill steel for transmitting the rotary motion of said piston to the drill steel, said means for intermittently holding said rifle bar against rotation comprising a reciprocable member coaxial with and splined to said rifle bar, a coaxial stationary member, clutch teeth on said reciprooable and stationary members adapted to engage each other to lock positively the rifle bar to said stationary member, said reciprocable member having a pressure area,

and means for subjecting said pressure area. intermittently to the action of pressure fluid having a controlling valve operable at will for .interrupting the flow of fluid to said pressurev area to permit the steel to remain stationary as regards rotary movement during reciprocation of the hammer piston.

9. A drill steel rotation mechanism comprising a rotation bar, a reciprocable member arranged coaxially With and splined to said rotation bar, a stationary member, clutch teeth on the reoiprocable and stationary members adapted to engage each other to lock positively the rotation bar against rotation, said reciprocable member having a pressure area, and means for intermittently supplying pressure uid to act on said pressure area to move said reciprocable member, intermittently into clutched relation with said stationary member having a controlling valve operable at will for interrupting the ow of fluid to said pressure area and venting the latter to atmosphere.

ELMER G. GARTIN. 

